Development of Prodrug 4-Chloro-3-(5-methyl-3-{[4-(2-pyrrolidin-1-ylethoxy)phenyl]amino}-1,2,4-benzotriazin-7-yl)phenyl Benzoate (TG100801): A Topically Administered Therapeutic Candidate in Clinical Trials for the Treatment of Age-Related Macular Degeneration

Abstract

Age-related macular degeneration (AMD) is one of the leading causes of loss of vision in the industrialized world. Attenuating the VEGF signal in the eye to treat AMD has been validated clinically. A large body of evidence suggests that inhibitors targeting the VEGFr pathway may be effective for the treatment of AMD. Recent studies using Src/YES knockout mice suggest that along with VEGF, Src and YES play a crucial role in vascular leak and might be useful in treating edema associated with AMD. Therefore, we have developed several potent benzotriazine inhibitors designed to target VEGFr2, Src, and YES. One of the most potent compounds is 4-chloro-3-{5-methyl-3-[4-(2-pyrrolidin-1-yl-ethoxy)phenylamino]benzo[1,2,4]triazin-7-yl}phenol ( 5), a dual inhibitor of both VEGFr2 and the Src family (Src and YES) kinases. Several ester analogues of 5 were prepared as prodrugs to improve the concentration of 5 at the back of the eye after topical administration. The thermal stability of these esters was studied, and it was found that benzoyl and substituted benzoyl esters of 5 showed good thermal stability. The hydrolysis rates of these prodrugs were studied to analyze their ability to undergo conversion to 5 in vivo so that appropriate concentrations of 5 are available in the back-of-the-eye tissues. From these studies, we identified 4-chloro-3-(5-methyl-3-{[4-(2-pyrrolidin-1-ylethoxy)phenyl]amino}-1,2,4-benzotriazin-7-yl)phenyl benzoate ( 12), a topically administered prodrug delivered as an eye drop that is readily converted to the active compound 5 in the eye. This topically delivered compound exhibited excellent ocular pharmacokinetics and poor systemic circulation and showed good efficacy in the laser induced choroidal neovascularization model. On the basis of its superior profile, compound 12 was advanced. It is currently in a clinical trial as a first in class, VEGFr2 targeting, topically applied compound for the treatment of AMD.

Applications of Palladium-Catalyzed C–N Cross-Coupling Reactions

“…Palanki and co-workers (TargeGen) identified prodrug candidate 333 , an inhibitor of Src kinase and VEGFr ( Scheme 72 b). 243 This compound was active against age-related macular degeneration, a main cause of vision loss. To obtain intermediate 332 , 4-(2-pyrrolidin-1-ylethoxy)bromobenzene was combined with 3-amino-1,2,4-triazine in moderate yield.…”

Horizons in Therapy for Corneal Angiogenesis

“…Currently, it is in clinical trials for the treatment of AMD and has potential application for corneal neovascularization. 37 …”

Recent Advances in Antiangiogenic Agents with VEGFR as Target

“…The results indicated that all the six VEGFR-2 active phthalazine derivatives (47-52, IC 50 = 48-120 nM) also displayed good activity against VEGFR-1 with the IC 50 330 nM range. Another two compounds (53, 54) showed good potential for the development as VEGFR-2 specific inhibitors (15-20 fold) against VEGFR-1.…”

“…The in vivo anticancer activity of (79) was identified in a L2987 human lung carcinoma xenografts in athymic mice. A series of substituted benzotriazines was disclosed as potent inhibitors of VEGFR by Palanki in 2008 [50]. One of the most potent compounds was (80), a dual inhibitor of both VEGFR-2 and Src family kinases.…”